1. Field of the Invention
This invention relates generally to an orthopedic apparatus that delivers a controlled amount of energy to an orthopedic site to contract collagen tissue, and more particularly, to an orthopedic apparatus that includes a handle with an actuating lever to deflect a distal end of a trocar, a locking lever to lock the position of a deflected distal end, wherein the deflection, locking, release and modification of the deflection are all achieved with a handle and the deflection and locking is achieved with a thumb and a finger of the same hand.
2. Description of Related Art
Instability of peripheral joints has long been recognized as a significant cause of disability and functional limitation in patients who are active in their daily activities, work or sports. Diarthrodial joints of musculoskeletal system have varying degrees of intrinsic stability based on joint geometry and ligament and soft tissue investment. Diarthrodial joints are comprised of the articulation of the ends of bones and their covering of hyaline cartilage surrounded by a soft tissue joint capsule that maintains the constant contact of the cartilage surfaces. This joint capsule also maintains within the joint the synovial fluid that provides nutrition and lubrication of the joint surfaces. Ligaments are soft tissue condensations in or around the joint capsule that reinforce and hold the joint together while also controlling and restricting various movements of the joints. The ligaments, joint capsule, and connective tissue are largely comprised of collagen.
When a joint becomes unstable, its soft tissue or bony structures allow for excessive motion of the joint surfaces relative to each other and in directions not normally permitted by the ligaments or capsule. When one surface of a joint slides out of position relative to the other surface, but some contact remains, subluxation occurs. When one surface of the joint completely disengages and loses contact with the opposing surface, a dislocation occurs. Typically, the more motion a joint normally demonstrates, the more inherently loose the soft tissue investment is surrounding the joint. This makes some joints more prone to instability than others. The shoulder, (glenohumeral) joint, for example, has the greatest range of motion of all peripheral joints. It has long been recognized as having the highest subluxation and dislocation rate because of its inherent laxity relative to more constrained xe2x80x9cball and socketxe2x80x9d joints such as the hip.
Instability of the shoulder can occur congenitally, developmentally, or traumatically and often becomes recurrent, necessitating surgical repair. In fact subluxations and dislocations are a common occurrence and cause for a large number of orthopedic procedures each year. Symptoms include pain, instability, weakness, and limitation of function. If the instability is severe and recurrent, functional incapacity and arthritis may result. Surgical attempts are directed toward tightening the soft tissue restraints that have become pathologically loose. These procedures are typically performed through open surgical approaches that often require hospitalization and prolonged rehabilitation programs.
More recently, endoscopic (arthroscopic) techniques for achieving these same goals have been explored with variable success. Endoscopic techniques have the advantage of being performed through smaller incisions and therefore are usually less painful, performed on an outpatient basis, are associated with less blood loss and lower risk of infection and have a more cosmetically acceptable scar. Recovery is often faster postoperatively than using open techniques. However, it is often more technically demanding to advance and tighten capsule or ligamentous tissue arthroscopically because of the difficult access to pathologically loose tissue and because it is very hard to determine how much tightening or advancement of the lax tissue is clinically necessary. In addition, fixation of advanced or tightened soft tissue is more difficult arthroscopically than through open surgical methods.
Collagen connective tissue is ubiquitous in the human body and demonstrates several unique characteristics not found in other tissues. It provides the cohesiveness of the musculoskeletal system, the structural integrity of the viscera as well as the elasticity of integument. These are basically five types of collagen molecules with Type I being most common in bone, tendon, skin and other connective tissues, and Type III is common in muscular and elastic tissues.
Intermolecular cross links provide collagen connective tissue with unique physical properties of high tensile strength and substantial elasticity. A previously recognized property of collagen is hydrothermal shrinkage of collagen fibers when elevated in temperature. This unique molecular response to temperature elevation is the result of rupture of the collagen stabilizing cross links and immediate contraction of the collagen fibers to about one-third of their original lineal distention. Additionally, the caliber of the individual fibers increases greatly, over four fold, without changing the structural integrity of the connection tissue.
There has been discussion in the existing literature regarding alteration of collagen connective tissue in different parts of the body. One known technique for effective use of this knowledge of the properties of collagen is through the use of infrared laser energy to effect tissue heating. The use of infrared laser energy as a corneal collagen shrinking tool of the eye has been described and relates to laser keratoplasty, as set forth in U.S. Pat. No. 4,976,709. The importance controlling the localization, timing and intensity of laser energy delivery is recognized as paramount in providing the desired soft tissue shrinkage effects without creating excessive damage to the surrounding non-target tissues.
Radiofrequency (RF) electrical current has been used to reshape the cornea. Such shaping has been reported by Doss in U.S. Pat. Nos. 4,326,529; and 4,381,007. However, Doss was not concerned with dissociating collagen tissue in his reshaping of the cornea.
Shrinkage of collagen tissue is important in many applications. One such application is the shoulder capsule. The capsule of the shoulder consists of a synovial lining and three well defined layers of collagen. The fibers of the inner and outer layers extend in a coronal access from the glenoid to the humerus. The middle layer of the collagen extends in a sagittal direction, crossing the fibers of the other two layers. The relative thickness and degree of intermingling of collagen fibers of the three layers vary with different portions of the capsule. The ligamentous components of the capsule are represented by abrupt thickenings of the inner layer with a significant increase in well organized coarse collagen bundles in the coronal plane.
The capsule functions as a hammock-like sling to support the humeral head. In pathologic states of recurrent traumatic or developmental instability this capsule or pouch becomes attenuated and the capsule capacity increases secondary to capsule redundance. In cases of congenital or developmental multi-directional laxity, an altered ratio of type I to type III collagen fibers may be noted. In these shoulder capsules a higher ratio of more elastic type III collagen has been described.
There is a need for an orthopedic apparatus for effecting a change in ligaments, joint capsules and connective tissue through the controlled contraction of collagen fibers. There is a need for an apparatus that includes a handle with a lateral deflection actuating member that is pulled and causes a distal end of the trocar to be deflected to a desired position, and a locking member on the handle which locks the distal end in a laterally deflected position, and is releasable to modify the amount of deflection of the deflected distal end.
Accordingly, an object of the invention is to provide an orthopedic apparatus that effects a change in ligaments, joint capsules and connective tissue through the controlled contraction of collagen fibers.
Another object of the invention is to provide an orthopedic apparatus, using an RF or microwave electrode, to effect a change in ligaments, joint capsules and connective tissue through the controlled contraction of collagen fibers.
A further object of the invention is to provide an orthopedic apparatus for the controlled contraction of collagen tissue that includes a trocar with a deflectable distal end, an RF or microwave electrode positioned at the distal end, and a handle that includes a actuating member to deflect the distal end and a locking member to lock the distal end in position. Deflection of the distal end and modification of the amount of deflection is achieved by a single hand.
Yet another object of the invention is to provide an orthopedic apparatus for the controlled contraction of collagen tissue that enables the surgeon to deflect a distal end of a trocar with an electrode surface, lock the deflection, modify the deflection, and permit the trocar to spring back to a non-deflected position with a thumb and a finger of only one hand.
Still a further object of the invention is to provide an orthopedic apparatus for the controlled contraction of collagen tissue that includes a handle which permits the physician to introduce a trocar of the orthopedic apparatus into a desired location of the body, and provide variable deflection of the distal end of the trocar in order to position the distal end at a desired located, and thereafter continue to modify the deflection in order to paint across selected collagen tissue surfaces to achieve a desired contraction of collagen tissue.
Yet another object of the invention is to provide an orthopedic apparatus, for the controlled contraction of collagen tissue, that includes a deflectable trocar distal end and a handle, with the handle permitting a quick modification of deflection, and easy return to a non-deflected position.
These and other objects of the invention are obtained in an orthopedic apparatus for effecting a change in ligaments, joint capsules and connective tissue through the controlled contraction of collagen fibers. A trocar includes a trocar elongated body with a trocar longitudinal axis, a trocar distal end that is laterally deflectable relative to the trocar longitudinal axis, and a trocar proximal end. An electrode is positioned at the trocar distal end. The electrode delivers substantially uniform energy across an energy delivery surface of the electrode. The energy delivery surface positioned next to an area of collagen fibers delivers a controlled amount of contraction of the collagen fibers while minimizing dissociation and breakdown of the collagen fibers. A handle is positioned at the proximal end of the trocar. The handle includes an actuating member and a locking member. The actuating member has a resting position and one or more activation positions. At the activation positions the trocar distal end becomes laterally deflected to a desired position of deflection. The locking member has a resting position and a locking position. The locking position locks the deflected trocar distal end in place. Further, the locking member is releasable from the locking position to the resting position or to a position that is intermediate between the two in order to modify the activation position of the actuating member and change the deflection of the trocar distal end. The distal end""s deflection can be readily adjusted and can also return to a non-deflected position. The handle can be held in one hand, and the actuating and locking members are each operable by a thumb and a finger of the hand.
The electrode can be an RF electrode, and the orthopedic apparatus can further include an RF energy source, and a cable that connects the RF energy source to the handle and the electrode.
Further, the electrode be a microwave electrode, and the orthopedic apparatus can include a microwave energy source, and a cable that connects the microwave energy source to the handle and the electrode.
The electrode preferably has radiused edges. An insulating layer is positioned around an exterior of the trocar but does not cover the energy delivery surface of the electrode. A non-conductive layer can also be included and positioned on an opposite side of the electrode. This provides an electrode with only one conductive surface and with radiused edges. The trocar is deflectable. Deflection can be achieved by serrating the trocar, making it out of a memory metal, as well as other methods well known to those skilled in the art. Both the locking and actuating members are coupled to the trocar. The actuating member can be pivotally coupled to the handle, while the locking member can be slideably positioned on a exterior surface of the handle. The actuating and locking members can be positioned on opposite sides of the handle so that one can be operated with the thumb, and the other one with a finger. Both the actuating and locking members can be moved simultaneously or at different times. This provides the physician with an ability to readily deliver energy from the electrode to a collagen tissue site, and move the electrode in conformance with the geometry of the collagen tissue site.
The handle design provides physician control of the movement of the electrode to closely approximate a desired collagen tissue site. This is readily achieved with the use of only one hand.